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Discussion on: Bringing Modern OO To Perl

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jplindstrom profile image
Johan Lindstrom • Edited on

I don't understand the argument. How is "it can't compile" backwards compatible? It's new syntax that should blow up in earlier versions. And it does.

Aside from that, a class declaration with / without a block seems to blow up the same way:

class Cache::LRU;            # to end of file
class Cache::LRU { ... };    # to end of block
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So what is the argument?

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ovid profile image
Ovid Author

This is something that was pointed out to me (by Sawyer? can't recall) a while ago as an unintended benefit. In short, if I wanted to repurpose syntax such as my Dog $spot, I'd be stepping on existing syntax. However, by creating a new syntax with an unambiguous scope and is guaranteed not to run on older versions of Perl (short of something really bizarre going on), we have a brand new syntax which is guaranteed not to clash with existing usage.

Further, because its scope is well-defined, we can play around with new syntax in that scope. Just adding a has function or a method keyword to the language could break all sorts of existing code that is already trying to do something like that. But by doing it in a new scope, we're safe.